Ionized air flow discharge type non-dusting ionizer

ABSTRACT

The ionizer of the present invention comprises a chamber which has an ionization part that ionizes a portion of an ion carrier gas that is supplied to the interior of this chamber, and a blowing part which feeds the ion carrier gas toward a charged body. The ionization part is constructed from an ionization source which is contained in the chamber, and a control device which is connected with this ionization source via a high-voltage cable. Either the generating part of a soft X-ray generating device, the generating part of a low-energy electron beam generating device or the generating part of an ultraviolet radiation generating device is used as the ionization source. The control device, the connecting part between the control device and the high-voltage cable and the connecting part between the ionization source and the high-voltage cable are formed with an explosion-proof structure.

TECHNICAL FIELD

[0001] The present invention relates to an ionizer which is used toeliminate static electricity, and more particularly relates to anionized gas current emission type dust-free ionizer which is an ionizerof a type that emits an ionized gas current toward the object of staticelectricity removal, and which can be used in explosion-proof facilitiesand equipment.

BACKGROUND ART

[0002] In recent years, in explosion-proof facilities such as facilitieswhere hazardous substances are handled or the like, clogging during theair feeding of combustible powders and clogging of sieves, as well asstatic charge build-up and discharge in the interiors of agitating tanksfor organic solvents or the like whose inside surfaces are coated withTeflon, have become problems. Conventionally, in the case of staticcharge build-up and discharge inside such agitating tanks, the ignitionof the organic solvents has been prevented by purging the air from thetanks with N₂ gas, so that oxygen that might lead to ignition iseliminated. In the case of such de-charging methods, however, theinitial costs and running costs of auxiliary facilities such as gassupply and exhaust facilities or the like are high, so that such methodsare not desirable.

[0003] Meanwhile, air ionizing devices which neutralize electricalcharges in charged bodies by means of ions have conventionally been usedas devices for eliminating static electricity in production environmentssuch as clean rooms or the like in which semiconductors, liquid crystaldisplays (hereafter referred to as “LCDs”) or the like are manufactured.Corona discharge type ionizers are commonly used as such air ionizingdevices. In the case of such corona discharge type ionizers, a highpositive or negative voltage is respectively applied to a positive ornegative electrode, so that a corona discharge is generated, and the airsurrounding the tip end of the abovementioned electrode is positivelyand negatively ionized; then, these ions are conveyed by air currents sothat the charges on charged bodies are neutralized by ions of theopposite polarity.

[0004] However, semiconductor and liquid crystal manufacturing deviceshave become progressively smaller over the years, and in the case ofconventional ionizers, it has become difficult to ensure an optimalinstallation space. Furthermore, the demand for static electricitycountermeasures in narrow spaces such as the gaps between glasssubstrates inside cassettes and the like has also increased.

Problems to Be Solved

[0005] Accordingly, when the present inventors investigated theabovementioned reduction in size of air ionizing devices, and theapplication of such devices to explosion-proof facilities and equipment,the inventors found that the following problem points exist.Specifically, in the case of corona discharge type ionizers commonlyused in the past, there is a considerable danger that the coronadischarge itself will become an ignition source; accordingly, it has notbeen possible to use such ionizers in explosion-proof facilities such asfacilities where hazardous substances are handled or the like.

[0006] Furthermore, in order to facilitate the generation of ions andprevent the consumption of generated ions, corona discharge typeionizers ionize the air in a state in which the electrodes are exposedin the vicinity of the object of de-charging. As a result, the followingproblems have also occurred.

[0007] (1) Generation of Ozone

[0008] Since the air in the vicinity of the object of de-charging isionized by a corona discharge, a reaction which converts oxygen intoozone occurs besides the ionization of nitrogen and water vapor in theair. The surfaces of silicon wafers are oxidized by the oxidizing actionof this ozone, and there are reactions with minute amounts of impuritiesin the air so that secondary particles are generated.

[0009] (2) Generation of Electromagnetic Noise

[0010] Irregular electromagnetic noise generated from the dischargeelectrode during the discharge may cause malfunctioning of precisioninstruments, computers or the like containing semiconductor elements.

[0011] (3) Generation of Dust from the Ion Generating Electrodes

[0012] The electrodes are consumed each time that a corona discharge iscaused to occur, and the consumed electrode material is scattered.Furthermore, minute amounts of gas components in the air are convertedinto particles by the corona discharge, and are deposited on the iongenerating electrodes, and when these particles reach a certain size,the particles are again scattered. As a result of such generation ofdust, the yield drops.

[0013] In recent years, furthermore, ionizers which use soft X-rays asan ionization source have been developed. However, since the connectingparts between [such] ionizers and electrical cables, and the controldevices for the ionization sources do not have explosion-proofspecifications, it has been impossible to use such ionizers inexplosion-proof facilities such as facilities handling hazardoussubstances or the like.

OBJECT OF THE INVENTION

[0014] The present invention has been proposed in order to solve suchproblem points encountered in the prior art; it is an object of thepresent invention to provide an ionized gas current emission typedust-free ionizer which makes it possible to take countermeasuresagainst static electricity in narrow spaces without causing thegeneration of ozone, electromagnetic noise, dust or the like, and whichis also devised so that this ionizer can be used in explosion-prooffacilities and equipment.

DISCLOSURE OF THE INVENTION

[0015] The present invention is an ionized gas current emission typedust-free ionizer which comprises a chamber having an ionization partthat ionizes a portion of an ion carrier gas that is supplied to theinterior of this chamber, and a blowing part that feeds the ion carriergas toward a charged body, and in which the abovementioned ionizationpart is constructed from an ionization source that is contained in theabovementioned chamber, and a control device which is disposed outsidethe abovementioned chamber and which controls the quantity of ionsgenerated by the abovementioned ionization source via a high-voltagecable, this ionizer being characterized in that the abovementionedionization source is either the generating part of a soft X-raygenerating device, the generating part of a low-energy electron beamgenerating device, or the generating part of an ultraviolet radiationgenerating device, and the abovementioned control device, the connectingpart between the abovementioned control device and the high-voltagecable, and the connecting part between the abovementioned ionizationsource and the high-voltage cable, [all] have an explosion-proofstructure.

[0016] In the ionized gas current emission type dust-free ionizer of thepresent invention, which has the abovementioned construction, since acorona discharge which might be a cause of ignition is not used as theionization source, the ignition of combustible substances such asorganic solvents or the like can be prevented. Furthermore, since thecontrol device is formed with an explosion-proof structure, the ignitionof combustible substances such as organic solvents or the like by thepower supply or control board disposed inside the control device can beprevented.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a model diagram which shows the construction of a firstembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0018]FIG. 2 (A) is a sectional view which shows the construction of theconnecting part between the high-voltage cable and the control device;

[0019]FIG. 2 (B) is a diagram showing a state in which packing has beeninstalled in the base end portion of the electrode supporting part;

[0020]FIG. 2 (C) is a sectional view which shows the construction of theconnecting part between the ionization source and the high-voltagecable;

[0021]FIG. 3 is a model diagram which shows the construction of a secondembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0022]FIG. 4 is a model diagram which shows the construction of a thirdembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0023]FIG. 5 is a model diagram which shows the construction of a fourthembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0024]FIG. 6 is a model diagram which shows the construction of a fifthembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0025]FIG. 7 is a model diagram which shows the construction of a sixthembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0026]FIG. 8 is a model diagram which shows the construction of aseventh embodiment of the ionized gas current emission type dust-freeionizer of the present invention;

[0027]FIG. 9 is a model diagram which shows the construction of aneighth embodiment of the ionized gas current emission type dust-freeionizer of the present invention;

[0028]FIG. 10 is a model diagram which shows the construction of a ninthembodiment of the ionized gas current emission type dust-free ionizer ofthe present invention;

[0029]FIG. 11 shows diagrams which illustrate the construction of theshielding part of the blowing port in the ninth embodiment of thepresent invention, with FIG. 11 (A) showing a case in which theshielding part is constructed from two punched plates, FIG. 11 (B)showing a case in which an aluminum honeycomb is disposed in theshielding part, and FIG. 11 (C) showing a case in which asleeve-equipped punched plate is disposed in the shielding part; and

[0030]FIG. 12 is a model diagram which shows the construction of otherembodiments of the ionized gas current emission type dust-free ionizerof the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0031] Concrete embodiments of the present invention will be describedbelow with reference to the attached figures.

(1) First Embodiment

[0032] (1-1) Construction

[0033] (1-1-1) Overall Construction

[0034]FIG. 1 is a model diagram which shows the overall construction ofthe ionized gas current emission type dust-free ionizer of the presentembodiment. In the same figure, 1 indicates a cylindrical ionizationchamber (hereafter referred to as a “chamber”); this chamber isconstructed from a metal such as aluminum, stainless steel or the like,or a resin such as polyvinyl chloride or the like. Furthermore, in termsof main parts, this chamber 1 is constructed from an ionization part, ashielding part and a blowing part. An ionization source 4 is disposed inthe interior of the chamber 1; this ionization source 4 is connected viaa high-voltage cable 6 to a control device 5 which controls the quantityof ions generated by the ionization source 4.

[0035] Furthermore, the ionized gas current emission type dust-freeionizer of the present invention has characterizing features in theconstruction of the control device 5, the construction of the connectingpart (part A in FIG. 1) between the control device 5 and high-voltagecable 6, and connecting part (part B in FIG. 1) between theabovementioned ionization source 4 and high-voltage cable 6. Theconstructions of these respective parts will be described in detailbelow.

[0036] (1-1-2) Construction of Control Device

[0037] As is shown in FIG. 1, the control device 5 is constructed froman air-tight chamber 51 which has an explosion-proof function.Furthermore, a control board 53 which is a control part that is used tocause the generation of soft X-rays, a low-energy electron beam orultraviolet radiation from the abovementioned ionization source 4, acirculating fan 54 which circulates cooled air or the like, and acooling device 55 which controls the interior of the device to aconstant temperature, are installed inside the control device 5.Furthermore, a power supply cable 56 is connected to the abovementionedcontrol board 53, and the control device 5 is thus adapted so that thisdevice can be connected to an explosion-proof socket (not shown in thefigures) installed on the outside. In the present embodiment,furthermore, the abovementioned cooling device 55 is constructed (forexample) by attaching a Peltier element (thermoelectric refrigeratingelement) to an aluminum heat dissipating plate.

[0038] (1-1-3) Construction of Connecting Part Between High-VoltageCable and Control Device

[0039]FIG. 2 (A) is an enlarged sectional view which shows theconstruction of the connecting part (part A in FIG. 1) between theabovementioned control device 5 and the high-voltage cable 6.Furthermore, as is described below, this connecting part hasexplosion-proof specifications.

[0040] Specifically, a plug 61 is attached to the tip end portion of thehigh-voltage cable 6; thus, the high-voltage cable 6 is adapted so thatthis cable can be detachably connected to a socket 71 disposed in theside wall of the control device 5. Furthermore, the abovementioned plug61 has a three-core structure, and electrodes 63 are attached to the tipends of electrode supporting parts 62 that have a specified length “L”.Furthermore, a cap nut 65 which has a screw part 64 formed on the insidewall is attached to the outside of the base part 61 a of theabovementioned plug 61 so that this nut can rotate.

[0041] Meanwhile, insertion holes 72 which engage with the electrodesupporting parts 62 that are formed on the abovementioned plug 61 areformed in the socket 71 that is disposed in the side wall of the controldevice 5, and electrodes 73 that are connected with the electrodes 63 onthe side of the abovementioned plug are formed in the deepest parts ofthese insertion holes 72. Furthermore, a screw part 74 is formed on theouter circumferential surface of the flange part 71 a of the socket 71,and the device is adapted so that [this screw part 74] engages with thescrew part 64 of the cap nut 65 attached to the abovementioned plug 61.

[0042] Furthermore, the length of the insertion holes 72 is set as “L”in correspondence to the electrode supporting parts 62 on the plug side,and this length “L” is set so that the attachment and detachment of bothsets of electrodes can be performed in air-tight spaces constructed bythe electrode supporting parts 62 of the plug 61 and the insertion holes72 of the socket 71. Furthermore, as is shown in FIG. 2 (B), packing 66such as O-rings or the like may be disposed on the base end portions ofthe electrode supporting parts 62 in order to maintain the air-tightnessof the connecting part between the plug 61 and the socket 71.

[0043] (1-1-4) Construction of Connecting Part Between Ionization Sourceand High-Voltage Cable

[0044] As is shown in FIG. 2 (c), the connecting part (part B in FIG. 1)between the ionization source 4 and the high-voltage cable 6 isconstructed by causing a pipe 41 made of a resin which has electricalinsulating properties such as a polyvinyl chloride, polypropylene,acrylic or the like through the side surface of the chamber 1, andfilling the interior of this pipe with an insulating resin 42 such as anepoxy resin or the like.

[0045] (1-1-5) Construction of Ionization Part

[0046] As is shown in FIG. 1, a slender tube (not shown in the figures)is connected to the side end portion (right side end portion in thefigure) of the chamber 1 via a tube fitting 2, and the device is thusadapted so that the air inside the chamber that is the object ofde-charging, or a non-reactive gas such as high-purity N₂ gas or thelike (hereafter referred to as the “ion carrier gas”) can be supplied tothe interior of the chamber 1 via this tube. Here, furthermore, the term“high-purity N₂ gas” refers to N₂ gas which contains enough oxygen orwater vapor to form negative ions, and which has an oxygen concentration(approximately 5% or less) that does not generate ozone.

[0047] Furthermore, an ionization source 4 is disposed near theinstallation position of the tube fitting 2 inside the chamber 1.Moreover, an ion generating device is formed by this ionization source 4and the abovementioned control device 5.

[0048] Furthermore, the abovementioned ionization source 4 comprises thegenerating part of a soft X-ray generating device, the generating partof a low-energy electron beam generating device, the generating part ofan ultraviolet radiation generating device or the like, and is adaptedso that this ionization source ionizes the ion carrier gas that flowsthrough the interior of the chamber 1.

[0049] (1-1-6) Construction of Shielding Part

[0050] In the present embodiment, as is shown in FIG. 1, the shieldingpart of the chamber 1 is formed by two punched plates 10 a and 10 b inwhich numerous fine holes 11 with a diameter of approximately 3 φ areformed. These two punched plates 10 a and 10 b are separated from eachother by a distance of approximately 3 mm, and are disposed in shiftedpositions so that the fine holes 11 do not overlap.

[0051] (1-1-7) Construction of Blowing Part

[0052] The tip end portion of the chamber 1 is opened; this part isdisposed in the vicinity of the charged body that is the object ofde-charging, and is adapted so that the positive and negative ionsgenerated in the abovementioned ion generating device are fed towardthis charged body.

[0053] (1-1-8) Ionization Source

[0054] Next, the ionization source 4 will be described.

[0055] Soft X-rays are extremely weak X-rays with an energy ofapproximately 3 to 9.5 keV. Furthermore, a low-energy electron beam isan electron beam (soft electron beam) which is extracted at a lowoperating voltage of several tens of kilovolts by means of (for example)a super-compact electron beam irradiation tube manufactured by UshioDenki K.K. or the like. This electron beam has a travel distance of onlyabout 5 cm in air, and ionizes air or gases in this region.

[0056] Furthermore, in the case of a low-energy electron beam, sincesoft X-rays are also generated at the same time that ozone is generatedin gases containing oxygen, shielding is necessary. Accordingly, incases where a low-energy electron beam is used as an ionization source,it is desirable to use a non-reactive gas whose oxygen content is smallenough that ozone is not generated, such as high-purity N₂ gas or thelike, as the ion carrier gas. Furthermore, the ultraviolet radiationgenerated by an ultraviolet radiation generating device isshort-wavelength radiation with a wavelength of 400 nm or less, and anoutput power of approximately 30 W.

[0057] In cases where the ionization source 4 is a soft X-ray generatingpart, either air or a non-reactive gas may be used as the ion carriergas that is supplied to the chamber 1; however, in cases where theionization source 4 is a low-energy electron beam generating part orultraviolet radiation generating part, it is desirable to a non-reactivegas whose oxygen content is small enough that ozone is not generated,such as high-purity N₂ gas or the like, as the ion carrier gas.

[0058] (1-2) Effects and Merits

[0059] Next the effects and merits of the ionized gas current emissiontype dust-free ionizer of the present embodiment, which has theconstruction described above, will be described.

[0060] Since the ionized gas current emission type dust-free ionizer ofthe present embodiment uses the generating part of a soft X-raygenerating device, the generating part of a low-energy electron beamgenerating device, the generating part of an ultraviolet radiationgenerating device or the like as an ionization source without using acorona discharge that might be a cause of ignition as this ionizationsource, the ignition of combustible substances such as organic solventsor the like can be prevented.

[0061] Furthermore, in the ionized gas current emission type dust-freeionizer of the present embodiment, a cooling device consisting of aPeltier element (thermoelectric cooling element) or the like is disposedinside the control device 5 that controls the quantity of ions generatedby the abovementioned ionization source, so that heat radiating from thecontrol board and heat sources disposed inside the control device, thusmaking it possible to control the interior of the device to a constanttemperature; accordingly, the control device can be formed with anair-tight structure. As a result, the ignition of combustible substancessuch as organic solvents or the like by the control board and heatsources disposed inside the device can be prevented.

[0062] Furthermore, since the connecting part between the high-voltagecable 6 and the control device 5 has an explosion-proof structure of thetype shown in FIG. 2, the attachment or detachment of the electrodes canbe performed in an air-tight space formed by the electrode supportingparts 62 of the plug 61 and the insertion holes 72 of the socket 71;accordingly, the ignition of combustible substances such as organicsolvents or the like caused by discharges during the attachment ordetachment of the plug can be prevented. Furthermore, since theconnecting part between the ionization source 4 and the high-voltagecable 6 also has an explosion-proof structure of the type shown in FIG.1, the ignition of combustible substances such as organic solvents orthe like in this connecting part can also be prevented.

[0063] Furthermore, in the ionized gas current emission type dust-freeionizer of the present embodiment, the ion carrier gas that is suppliedto the chamber 1 via a tube (not shown in the figures) and the tubefitting 2 is converted into positive and negative ions by irradiationwith soft X-rays, a low-energy electron beam, ultraviolet radiation orthe like by the ionization source 4 contained in the chamber 1.Furthermore, these positive and negative ions pass through the shieldingpart installed on the downstream side of the ionization part, and aresupplied to the charged body that constitutes the object of de-chargingfrom the tip end portion of the chamber 1, so that the positive andnegative charges of opposite polarity on the charged body can berespectively neutralized.

[0064] Thus, in the ionized gas current emission type dust-free ionizerof the present embodiment, in cases where the ionization source 4 is asoft X-ray generating part, there is no generation of ozone, regardlessof whether air or a non-reactive gas is used as the ion carrier gas.Furthermore, there is no generation of dust such as the scattering ofelectrode materials or deposition and re-scattering of impurities in theair, and there is likewise no generation of electromagnetic noise.

[0065] Furthermore, in cases where the ionization source 4 is alow-energy electron beam or ultraviolet radiation generating part, sincea non-reactive gas whose oxygen content is small enough that there is nogeneration of ozone, such as high-purity N₂ gas or the like, is used asthe ion carrier gas, there is no generation of ozone, no generation ofdust and no generation of electromagnetic noise during ionization.

[0066] Furthermore, soft X-rays or a low-energy electron beam can besufficiently blocked by a thin polyvinyl chloride plate or the like, sothat there is almost no reflection; accordingly, shielding can beaccomplished using a simple structure of the type shown in FIG. 1.Moreover, since the distance from the ionization source 4 to the chamberoutlet port is short, the following advantage is also obtained: namely,there is almost no decrease in ions due to the re-coupling of positiveand negative ions.

[0067] Furthermore, as a result of the installation of theabovementioned shielding part, the disturbance of the gas current fromthe chamber blowing port can be reduced; accordingly, the followingmerit is also obtained: namely, the decrease in the quantity of ionscaused by disturbance of the gas current can be ameliorated.

[0068] Furthermore, since the ionization source 4 and the control device5 constituting the power supply part and control part of this ionizationsource 4 are installed separately with a high-voltage cable interposed,and since only the ionization source 4 is disposed inside the chamber 1,the internal diameter of the chamber 1 can be reduced; accordingly, thefollowing merits can be obtained: namely, ions can be generated in anextremely narrow space, and de-charging can be performed even in thecase of a narrow space such as (for example) the gaps between glasssubstrates accommodated inside a cassette.

[0069] Thus, the ionized gas current emission type dust-free ionizer ofthe present embodiment makes it possible to obtain an ionizer whichallows countermeasures against static electricity to be taken in anarrow space without generating ozone, electromagnetic noise or dust,and which can be used in explosion-proof facilities and equipment.

(2) Second Embodiment

[0070] The present embodiment is a modification in which theconstruction of the shielding part of the abovementioned firstembodiment is altered.

[0071] In the present embodiment, as is shown in FIG. 3, the shieldingpart of the chamber 1 is constructed from two semi-circular partitionwalls 7, 7; these partition walls 7, 7 are alternately formed on theupper part and lower part of the chamber 1 so that a fixed gap is left.Specifically, in cases where the ionization source 4 is a soft X-raygenerating part or low-energy electron beam generating part, the systemis adapted so that the linearly advancing soft X-rays or electron beamelectrons strike the partition walls 7, 7, thus providing a constructionin which shielding is provided so that these soft X-rays or electrons donot leak to the outside. Furthermore, in cases where the ionizationsource 4 is an ultraviolet radiation generating part, this shieldingpart is unnecessary. The remaining construction is the same as in theabovementioned first embodiment; accordingly, a description is omitted.

[0072] The ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, has thesame effects and merits as the abovementioned first embodiment; thisionizer can be used in explosion-proof facilities and equipment, and canform the area on the downstream side of the ionization part of thechamber 1 into a shielding structure by means of a simple construction.

(3) Third Embodiment

[0073] The present embodiment is a modification in which theconstruction of the blowing part of the abovementioned first embodimentis altered. Furthermore, it goes without saying that the blowing part ofthe present embodiment can also be applied to the abovementioned secondembodiment.

[0074] In the present embodiment, as is shown in FIG. 4, a nozzle 20which is used to cause jetting of the ionized gas current is disposed onthe downstream side of the shielding part of the chamber 1. For example,a nozzle 216, flat nozzle 920, air curtain 302-306, air knife 392-396 orthe like manufactured by SILVENT Co. can be used as the abovementionednozzle 20.

[0075] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, the sameeffects and merits as those of the abovementioned first embodiment orsecond embodiment can be obtained; moreover, since a nozzle 20 which hasa desired shape and size is attached to the blowing part, the ionizedgas current can be blown onto the charged body at a high velocity, sothat dirt or the like adhering to the charged body can be removed with ahigh efficiency while the charged body is de-charged. Furthermore, byselecting various types of nozzles 20, it is possible to broaden theionized gas current at a wide angle in a conical shape, or to spread theionized gas current into the form of an air curtain; accordingly, theionized gas current can be controlled in accordance with the object ofde-charging. Furthermore, by using a nozzle that allows adjustment ofthe degree of opening, it is easily possible to alter the jet velocityof the ionized gas current.

(4) Fourth Embodiment

[0076] The present embodiment is a modification in which theconstruction of the blowing part of the abovementioned third embodimentis further altered.

[0077] In the present embodiment, as is shown in FIG. 5, a flexible hose30 is attached to the blowing part of the chamber 1, and a nozzle 31 isattached to the tip end of this flexible hose 30. Furthermore, as in theabovementioned third embodiment, a nozzle 216, flat nozzle 920, aircurtain 302-306, air knife 392-396 or the like manufactured by SILVENTCo. can be used as the abovementioned nozzle 31. Furthermore, thisflexible hose 30 differs from a vinyl tube or the like in that this hosehas a structure can maintain a set shape.

[0078] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, since aflexible hose 30 is attached to the blowing part and a nozzle 31 isfurther attached to the tip end of this flexible hose 30, not only canthe same effects and merits as those of the abovementioned first throughthird embodiments be obtained, but it is also possible blow the ionizedgas current onto the charged body at a high velocity, so that dirt orthe like adhering to the charged body can be removed with a highefficiency while the charged body is de-charged. Furthermore, byselecting various types of nozzles 31, it is possible to broaden theionized gas current at a wide angle in a conical shape, or to spread theionized gas current into the form of an air curtain; accordingly, theionized gas current can be controlled in accordance with the object ofde-charging. Furthermore, by using a nozzle that allows adjustment ofthe degree of opening, it is easily possible to alter the jet velocityof the ionized gas current.

(5) Fifth Embodiment

[0079] The present embodiment is an embodiment in which the shieldingpart and blowing part are constructed as an integral unit.

[0080] In the present embodiment, as is shown in FIG. 6, one or aplurality of openings (holes with a diameter of approximately 1 φ) 40which are of a size that can block X-rays or the like are formed (inaccordance with the object of de-charging) in a portion of the chamber(e. g., side surface) on the downstream side of the ionization source 4.Furthermore, in the present embodiment, these openings 40 function as ashielding part and a blowing part.

[0081] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, since aplurality of openings which are of a size that can block X-rays areformed in a portion of the chamber on the downstream side of theionization source 4, the jetting of an ionized gas current toward theobject of de-charging can be accomplished simultaneously with shielding.Furthermore, as will be described below, the present embodiment isespecially effective in cases where de-charging is performed by blowingan ionized gas current into the deep portions of narrow spaces such asthe gaps between glass substrates in a cassette or the like.

(6) Sixth Embodiment

[0082] The ionized gas current emission type dust-free ionizer of thepresent embodiment has characterizing features in the construction ofthe blowing port. Specifically, as is shown in FIG. 7, the blowing port81 in the present embodiment is formed in a cylindrical or prismaticshape, and a chamber 82 and duct 83 are connected to the upstream sideof this blowing port 81. Furthermore, the duct 83 comprises piping whichis used to supply air or a non-reactive gas such as high-purity N₂ gasor the like (hereafter referred to as the “ion carrier gas”) to theobject of de-charging in an explosion-proof facility via theabovementioned chamber 82 and blowing port 81. Moreover, the chamber 82is formed (for example) in the shape of a cone or square pyramid so thatthe cross-sectional area on the downstream side is larger than that onthe upstream side, and the end portion on the upstream side is connectedto the abovementioned duct 83, while the end portion on the downstreamside is connected to the abovementioned blowing port 81. Furthermore, itgoes without saying that the chamber 82 and blowing port 81 can also beconstructed as an integral unit.

[0083] Furthermore, a shielding part 84 is disposed in the vicinity ofthe tip end portion of the abovementioned blowing port 81. As is shown(for example) in FIG. 7, this shielding part 84 is constructed from twopunched plates 86 a and 86 b with a thickness of 1 mm in which numerousfine holes 85 with a diameter of approximately 5 mm φ and an openingpitch of approximately 12 mm are formed. These two punched plates 86 aand 86 b are separated from each other by a distance of approximately 3mm, and are disposed in positions that are shifted so that theabovementioned fine holes 85 do not overlap. Furthermore, the tip endportion of the blowing port 81 is open, and is disposed in the vicinityof the charged body S; the system is thus adapted so that positive andnegative ions generated in the ion generating device are fed toward thischarged body S.

[0084] Furthermore, an ion generating device is disposed in the sideportion of the abovementioned blowing port 81. This ion generatingdevice is constructed from an ionization source 4 which is disposed inthe side portion of the blowing port 81, and a control device 5 whichcontrols the quantity of ions generated by this ionization source 4.Furthermore, this control device 5 is disposed on the outside of theblowing port 81, and consists of a power supply part and control partwhich are used to generate soft X-rays or ultraviolet radiation from theionization source; the control device 5 is connected to the ionizationsource 4 by a high-voltage cable 6.

[0085] Furthermore, the construction of this control device 5, theconstruction of the connecting part between the high-voltage cable 6 andthe control device 5, and the construction of the connecting partbetween the ionization source 4 and the high-voltage cable 6, are thesame as in the abovementioned first embodiment; accordingly, adescription is omitted.

[0086] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, thisionizer can be used in explosion-proof facilities and equipment;furthermore, since the ionization source 4 is contained internally inthe vicinity of the outlet part of the blowing port 81, the ion carriergas can be ionized in the vicinity of the blowing port 81, so thationized air or the like can be supplied to the desired object ofde-charging. Furthermore, since the ionization source 4 is containedinternally in the side portion of the blowing port 81, and irradiationwith radiation such as soft X-rays or the like is performed horizontallywith the blowing port, a broad range can be covered by a singleionization source. Furthermore, since the ionization source 4 iscontained internally in the vicinity of the outlet part of the blowingport 81, the distance from the ionization source 4 to the outlet of theblowing port is short, so that the following merit is also obtained:namely, there is little decrease in the ions due to the re-coupling ofpositive and negative ions.

(7) Seventh Embodiment

[0087] This embodiment is a modification in which the installationposition of the ionization source of the abovementioned sixth embodimentis altered. Specifically, in the present embodiment, as is shown in FIG.8, the ionization source 4 is disposed in the central portion of achamber 82 which is formed in the shape of a cone or square pyramid. Theremaining construction is the same as in the abovementioned sixthembodiment; accordingly, a description is omitted. Furthermore, theionization source that can be disposed as shown in FIG. 8 is a softX-ray or ultraviolet radiation generating part.

[0088] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the construction described above, not onlycan the same effects and merits as in the abovementioned sixthembodiment be obtained, but it also possible to perform ionization overa broad range with a small ionization source in the case of anionization source that can emit soft X-rays or the like over a broadangle. Accordingly, since the ionization efficiency is good, and thequantity of ions generated is increased, the de-charging performance isimproved. Furthermore, the angle of incidence of the radiation on theshielding plates is greater than in cases where irradiation is performedhorizontally in the vicinity of the shielding plates; accordingly,shielding is facilitated, and shielding plate with vertical holes or thelike are unnecessary.

(8) Eighth Embodiment

[0089] This embodiment is a modification of the abovementioned sixthembodiment, and indicates a case in which an HEPA filter or ULPA filteris disposed on the upstream side of the blowing port. Specifically, inthe present embodiment, as is shown in FIG. 9, a laminar flow formingfilter 91 such as a HEPA filter, ULPA filter or the like is disposed onthe upstream side of the blowing port 81, and the system is adapted sothat the ion carrier gas that is fed in via the duct 83 and chamber 82can be formed into a gas current that has a uniform flow velocitydistribution over the entire surface of the blowing port 81.Furthermore, in the present embodiment, the ionization source 4 isdisposed in the vicinity of the side wall portion between theabovementioned laminar flow forming filter 91 and the shielding part 84.The remaining construction is the same as in the abovementioned sixthembodiment; accordingly, a description is omitted.

[0090] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the abovementioned construction, not onlycan the same effects and merits as those of the abovementioned sixthembodiment be obtained, but it is also possible to form the ion carriergas that is fed in from the chamber 82 into a laminar flow, since alaminar flow forming filter 91 is disposed on the upstream side of theblowing port 81. As a result, in cases where a turbulent flow (jet) issupplied to the blowing port, the problem of a decrease in the quantityof ions and a drop in the de-charging efficiency due to the promotion ofthe re-coupling of positive and negative ions by the mixing effect canbe prevented; accordingly, more efficient ionization can beaccomplished, so that a superior de-charging performance can beobtained.

(9) Ninth Embodiment

[0091] The ionized gas current emission type dust-free ionizer of thepresent embodiment is a modification of the abovementioned sixthembodiment. In this ionizer, as is shown in FIGS. 10 and 11, a laminarflow forming filter 91 such as a HEPA filter, ULPA filter or the like isdisposed on the upstream side of the blowing port 81, and an aluminumhoneycomb 92 which has vertical holes is disposed on the upstream sideof the two punched plates 86 a and 86 b disposed in the shielding part84 of the blowing port 81. Furthermore, it would also be possible toinstall a sleeve-equipped punched plate 93 such as that shown in FIG. 11(C) instead of installing an aluminum honeycomb 92 with vertical holes.The remaining construction is that same as that of the abovementionedsixth embodiment; accordingly, a description is omitted.

[0092] In the ionized gas current emission type dust-free ionizer of thepresent embodiment, which has the abovementioned construction, theionizer can be used in explosion-proof facilities and equipment;furthermore, since a laminar flow forming filter 91 is disposed on theupstream said of the blowing port 81, the ion carrier gas that is fed infrom the chamber 82 can be formed into a laminar flow. As a result, incases where a turbulent flow (jet) is supplied to the blowing port, theproblem of a decrease in the quantity of ions and a drop in thede-charging efficiency due to the promotion of the re-coupling ofpositive and negative ions by the mixing effect can be prevented;accordingly, more efficient ionization can be accomplished, so that asuperior de-charging performance can be obtained.

[0093] Furthermore, as is shown in FIG. 11 (A), in cases where twopunched plates 86 a and 86 b are respectively disposed with a specifiedgap between the plates in positions that are shifted so that the fineholes formed in the respective plates do not overlap, it is difficult tocompletely block radiation such as soft X-rays or the like that isincident on the fine holes of the punched plates 86 a and 86 b at aninclination from above. However, in the blowing port of the presentembodiment shown in FIG. 10, soft X-rays that are incident at aninclination from above are completely blocked by striking the side wallsof the vertical hole parts in the aluminum honeycomb 92 as shown in FIG.11 (B), or are completely blocked by striking the side walls of thesleeve of the sleeve-equipped punched plate 93 as shown in FIG. 11 (C).

(10) Other Embodiments

[0094] Furthermore, the present invention is not limited to theembodiments described above; various configurations such as thosedescribed below are possible. Specifically, the shapes or attachmentpositions and methods of respective concrete members may beappropriately altered. For example, the shape of the shielding part isnot limited to the punched plates indicated in the respectiveembodiments described above; any shape that is capable of preventing theleakage of linearly advancing soft X-rays, low-energy electron beamelectrons or the like to the outside, and that can carry the positiveand negative ions that are generated, may be used.

[0095] Furthermore, the ionization source 4 is not limited to softX-rays, a low-energy electron beam or ultraviolet radiation; otherelectromagnetic waves, beams or the like may be used as long as thesesources do not generate ozone, dust or electromagnetic noise as a resultof ionization. Moreover, as shown in FIG. 12, a construction in which anair supply fan 94 is incorporated may be applied.

INDUSTRIAL APPLICABILITY

[0096] As was described above, the present invention can provide anionized gas current emission type dust-free ionizer which makes itpossible to take countermeasures against static electricity in a narrowspace without causing the generation of ozone, electromagnetic noise,dust or the like, and which can also be used in explosion-prooffacilities and equipment.

1. An ionized gas current emission type dust-free ionizer whichcomprises a chamber having an ionization part that ionizes a portion ofan ion carrier gas that is supplied to the interior of this chamber, anda blowing part that feeds the ion carrier gas toward a charged body, andin which said ionization part is constructed from an ionization sourcethat is contained in said chamber, and a control device which isdisposed outside said chamber and which controls the quantity of ionsgenerated by said ionization source via a high-voltage cable, thisionizer being characterized in that: said ionization source is eitherthe generating part of a soft X-ray generating device, the generatingpart of a low-energy electron beam generating device, or the generatingpart of an ultraviolet radiation generating device; said chamber isformed in a cylindrical shape, and is adapted so that said ion carriergas is supplied to the vicinity of the ionization source inside saidchamber from the side end portion of said chamber; and a shielding partwhich is used to block the soft X-rays or low-energy electron beamgenerated by said ionization source is formed between said ionizationsource and blowing part.
 2. An ionized gas current emission typedust-free ionizer which comprises a chamber having an ionization partthat ionizes a portion of an ion carrier gas that is supplied to theinterior of this chamber, and a blowing part that feeds the ion carriergas toward a charged body, and in which said ionization part isconstructed from an ionization source that is contained in said chamber,and a control device which is disposed outside said chamber and whichcontrols the quantity of ions generated by said ionization source via ahigh-voltage cable, this ionizer being characterized in that: saidionization source is either the generating part of a soft X-raygenerating device, the generating part of a low-energy electron beamgenerating device, or the generating part of an ultraviolet radiationgenerating device; said chamber is formed in the shape of a cone orpyramid in which the cross-sectional area on the downstream side isgreater than the cross-sectional area on the upstream side, acylindrical or prismatic blowing part is disposed on the downstream sideof said chamber, said ionization source is disposed in the vicinity ofthe outlet part of said blowing part; and a shielding part which is usedto block the soft X-rays or low-energy electron beam generated by saidionization source is formed in the vicinity of the tip end portion ofsaid blowing part.
 3. An ionized gas current emission type dust-freeionizer which comprises a chamber having an ionization part that ionizesa portion of an ion carrier gas that is a supplied to the interior ofthis chamber, and a blowing part that feeds the ion carrier gas toward acharged body, and in which said ionization part is constructed from anionization source that is contained in said chamber, and a controldevice which is disposed outside said chamber and which controls thequantity of ions generated by said ionization source via a high-voltagecable, this ionizer being characterized in that: said ionization sourceis either the generating part of a soft X-ray generating device, thegenerating part of a low-energy electron beam generating device, or thegenerating part of an ultraviolet radiation generating device; saidchamber is formed in the shape of a cone or pyramid in which thecross-sectional area on the downstream side is greater than thecross-sectional area on the upstream side, a cylindrical or prismaticblowing part is disposed on the downstream side of said chamber, saidionization source is disposed in the central portion of said chamber;and a shielding part which is used to block the soft X-rays orlow-energy electron beam generated by said ionization source is formedin the vicinity of the tip end portion of said blowing part.
 4. Theionized gas current emission type dust-free ionizer according to claim1, characterized in that said control device has an air-tight structure,and comprises cooling means capable of maintaining the interior of thedevice at a constant temperature.
 5. The ionized gas current emissiontype dust-free ionizer according to claim 4, characterized in that saidcooling means are constructed from a thermoelectric refrigeratingelement.
 6. The ionized gas current emission type dust-free ionizeraccording to claim 1, characterized in that: the connecting part betweensaid high-voltage cable and control device is constructed from a plugand socket that can be attached and detached, electrode supporting partswhich have a specified length are disposed in said plug, electrodes aredisposed on the tip end portions of these electrode supporting parts,insertion holes into which said electrode supporting parts are insertedare formed in said socket, electrodes are disposed in the innermostparts of these insertion holes; a stopper which is used to maintain theengagement with said socket is disposed on the outside of the base partof said plug, and an air-tightness maintaining member is disposed on thebase end portions of said electrode supporting parts; the electricalconnection between said high-voltage cable and control device isaccomplished by electrodes which are disposed on the tip end of saidplug and electrodes which are disposed in the innermost parts of theinsertion holes of the socket; and said plug and socket are adapted sothat the attachment and detachment of said electrodes can be performedin a state in which an air-tight state between the electrode supportingparts of said plug and the insertion holes of the socket is maintained.7. The ionized gas current emission type dust-free ionizer according toclaim 1, characterized in that the connecting part between saidionization source and high-voltage cable is formed by a tubular resinthat has insulating properties, and an insulating resin with which theinterior of said tubular resin is filled.
 8. The ionized gas currentemission type dust-free ionizer according to claim 1, characterized inthat said shielding part is constructed from a plurality of partitionwalls which are alternately disposed on the inside walls of said chamberwith a specified gap.
 9. The ionized gas current emission type dust-freeionizer according to claim 1, characterized in that said shielding partis constructed from at least two shielding plates in which a pluralityof fine holes are formed, and said shielding plates are disposed so thatsaid fine holes do not overlap.
 10. The ionized gas current emissiontype dust-free ionizer according to claim 2, characterized in that saidshielding part is constructed from a shielding plate having a honeycombstructure.
 11. The ionized gas current emission type dust-free ionizeraccording to claim 2, characterized in that said shielding part isconstructed from a shielding plate with sleeves.
 12. The ionized gascurrent emission type dust-free ionizer according to claim 1,characterized in that said blowing part is constructed from a nozzlewith a specified shape which is attached to the open end of saidchamber.
 13. The ionized gas current emission type dust-free ionizeraccording to any claim 1, characterized in that said blowing part isconstructed from a flexible hose attached to the open end of saidchamber, and a nozzle with a specified shape which is attached to thetip end thereof.
 14. The ionized gas current emission type dust-freeionizer according to claim 1, characterized in that a plurality ofopenings are formed in one portion of the downstream-side side surfaceof said chamber, and the chamber is adapted so that the soft X-rays orlow-energy electron beam generated by said ionization source are blockedby these openings, and so that the ion carrier gas is supplied to thecharged body via these openings.
 15. The ionized gas current emissiontype dust-free ionizer according to claim 2, characterized in that alaminar flow forming filter is disposed on the upstream side of saidionization source.
 16. The ionized gas current emission type dust-freeionizer according to claim 2, characterized in that said control devicehas an air-tight structure, and comprises cooling means capable ofmaintaining the interior of the device at a constant temperature. 17.The ionized gas current emission type dust-free ionizer according toclaim 3, characterized in that said control device has an air-tightstructure, and comprises cooling means capable of maintaining theinterior of the device at a constant temperature.
 18. The ionized gascurrent emission type dust-free ionizer according to claim 2,characterized in that: the connecting part between said high-voltagecable and control device is constructed from a plug and socket that canbe attached and detached, electrode supporting parts which have aspecified length are disposed in said plug, electrodes are disposed onthe tip end portions of these electrode supporting parts, insertionholes into which said electrode supporting parts are inserted are formedin said socket, electrodes are disposed in the innermost parts of theseinsertion holes; a stopper which is used to maintain the engagement withsaid socket is disposed on the outside of the base part of said plug,and an air-tightness maintaining member is disposed on the base endportions of said electrode supporting parts; the electrical connectionbetween said high-voltage cable and control device is accomplished byelectrodes which are disposed on the tip end of said plug and electrodeswhich are disposed in the innermost parts of the insertion holes of thesocket; and said plug and socket are adapted so that the attachment anddetachment of said electrodes can be performed in a state in which anair-tight state between the electrode supporting parts of said plug andthe insertion holes of the socket is maintained.
 19. The ionized gascurrent emission type dust-free ionizer according to claim 3,characterized in that: the connecting part between said high-voltagecable and control device is constructed from a plug and socket that canbe attached and detached, electrode supporting parts which have aspecified length are disposed in said plug, electrodes are disposed onthe tip end portions of these electrode supporting parts, insertionholes into which said electrode supporting parts are inserted are formedin said socket, electrodes are disposed in the innermost parts of theseinsertion holes; a stopper which is used to maintain the engagement withsaid socket is disposed on the outside of the base part of said plug,and an air-tightness maintaining member is disposed on the base endportions of said electrode supporting parts; the electrical connectionbetween said high-voltage cable and control device is accomplished byelectrodes which are disposed on the tip end of said plug and electrodeswhich are disposed in the innermost parts of the insertion holes of thesocket; and said plug and socket are adapted so that the attachment anddetachment of said electrodes can be performed in a state in which anair-tight state between the electrode supporting parts of said plug andthe insertion holes of the socket is maintained.
 20. The ionized gascurrent emission type dust-free ionizer according to claim 2,characterized in that the connecting part between said ionization sourceand high-voltage cable is formed by a tubular resin that has insulatingproperties, and an insulating resin with which the interior of saidtubular resin is filled.
 21. The ionized gas current emission typedust-free ionizer according to claim 3, characterized in that theconnecting part between said ionization source and high-voltage cable isformed by a tubular resin that has insulating properties, and aninsulating resin with which the interior of said tubular resin isfilled.
 22. The ionized gas current emission type dust-free ionizeraccording to claim 2, characterized in that said shielding part isconstructed from a plurality of partition walls which are alternatelydisposed on the inside walls of said chamber with a specified gap. 23.The ionized gas current emission type dust-free ionizer according toclaim 3, characterized in that said shielding part is constructed from aplurality of partition walls which are alternately disposed on theinside walls of said chamber with a specified gap.
 24. The ionized gascurrent emission type dust-free ionizer according to claim 2,characterized in that said shielding part is constructed from at leasttwo shielding plates in which a plurality of fine holes are formed, andsaid shielding plates are disposed so that said fine holes do notoverlap.
 25. The ionized gas current emission type dust-free ionizeraccording to claim 3, characterized in that said shielding part isconstructed from at least two shielding plates in which a plurality offine holes are formed, and said shielding plates are disposed so thatsaid fine holes do not overlap.
 26. The ionized gas current emissiontype dust-free ionizer according to claim 3, characterized in that saidshielding part is constructed from a shielding plate having a honeycombstructure.
 27. The ionized gas current emission type dust-free ionizeraccording to claim 3, characterized in that said shielding part isconstructed from a shielding plate with sleeves.
 28. The ionized gascurrent emission type dust-free ionizer according to claim 2,characterized in that said blowing part is constructed from a nozzlewith a specified shape which is attached to the open end of saidchamber.
 29. The ionized gas current emission type dust-free ionizeraccording to claim 3, characterized in that said blowing part isconstructed from a nozzle with a specified shape which is attached tothe open end of said chamber.
 30. The ionized gas current emission typedust-free ionizer according to any claim 2, characterized in that saidblowing part is constructed from a flexible hose attached to the openend of said chamber, and a nozzle with a specified shape which isattached to the tip end thereof.
 31. The ionized gas current emissiontype dust-free ionizer according to any claim 3, characterized in thatsaid blowing part is constructed from a flexible hose attached to theopen end of said chamber, and a nozzle with a specified shape which isattached to the tip end thereof.